Process for the production of telomer acids



Nov.` 11, 1958 W. s. BARNHART ET A1. 2,860,150

PROCESS FOR THE: PRODUCTION OF TELOMER ACIDS Filed 001:. 18, 1955 523mb @Q v9 m9 mmmmDmUm. 0I

mmv H INVENTORS WILLIAM S- BARNHART ROBERT H. WADE ll. gime!- TTOR EYS I1. IIIIIL a 23.6 mmodb.

l l l l PROCESS FOR THE PRODUCTION OF TELOMER ACIDS William S. Barnhart, Cranford, and Robert H. Wade, West Paterson, N. I., assignors, by mesne assignments, to Minnesota Mining and Manufacturing Company, St. Paul, Minn., a corporation of Delaware Application October 18, 1955, Serial `No. 541,212 7 Claims. (Cl. 260-408) This invention relates to a chemical process and plant design for the preparation ofvt'elomer acids.

In copending application Serial No. 452,705, tiled August 27, 1954, now Patent No. 2,806,866, there is disclosed a new class of telomer acids which are prepared formula C1(CF2CFC1) 1CF2COOH and diacids having the formula HoC-(cF,-cFc1) ,cooH

in which n is'an integer from 2 to 16, theseyacids being produced by the hydrolysis of the telomerization `product of chlorotriiluoroethylene with sulfuryl chloride, the telomer having the formula i in which n is as given above. Thetelomer acids have many uses such as emulsiers in aqueous polymerization systems, as disclosed in copending application Serial No. 463,073, tiled October 18, 1954, and also have'many other uses as surfactants, Vas disclosed in copending application Serial No. 526,537, iiled August 4, 1955.

In accordance with the present invention, a process is` provided whereby telomer acids may be produced in` large quantities and in high yield. In the process of the invention, a perhalogenated telomer and oleum are charged to a reactor and maintained at an elevated temperature and pressure until the reaction is complete. The quantity of oleum charged to the reactor may be in the range of about 2 to l0 moles per mole of telo-mer, and the oleum may have a concentration of from about 1 to 70 percent free sulfur trioxide, although it is preferred to use oleum having a concentration range from about l to 20 percent free sulfur trioxide.

The reaction temperature is preferably in the range of about 200 to 225 C. At temperatures below 200 C. reaction occurs, but the rate is suiciently slowed that it is economically unattractive; at temperatures above 225 C.

reaction also occurs, but the rate of diacid formation is` greatly increased. The reaction time may be between about to about 40 hours, but the highest yields of desired products with the minimum amount of by-product formation have been obtained when operating at a tempen` ature of about 225 C. for aperiod of about 27hours. The reaction pressure may be in the range of atmospheric to 150 p. s. i. g. and is preferably in the range of about atmospheric to 50 p. s. i. g. At the completion of the react United States Patent C N"ice tion period, the reaction mixture is cooled to a temperature of vabout 100 C. by indirect heat exchange and is transferred to a drowning tank where it is cooled and diluted with water to eect the separation of a productA layer and a sulfuric acid layer. The cooling and dilution of there-x action mixture is conveniently effected by the ,addition of ice thereto, with or without additional Water, if desired.`

Cooling and dilution of the reaction mixture in, theV drowning tank constitutes a simple and effective means for the separation `of the desiredtelomer acid product layer from the sulfuric acid layer, since the solubility of telomer acids in dilute sulfuric acid, having afconcentra# tion in the range ofabout 50 to 70 percent, is Very loW. This low solubility is shown by the following table `in which are listed solubility data for certain telomer mono, and diacids, formed by the hydrolysis of telomerization products of chlorotriuoroethylene with sulfuryl chloride, in 50 percent by weight sulfuric acid:

TABLE i l Mg. acid! Wt.Pereent ml. solution Soluble P 'lelomer Acid Cs mono C10 mono C@ rliarirl 99.0.@ @NON @5055 a Density of 50% HzSOi is 1.395 g./m1.

l awash tank where they are washed with dilute hydro` chloric acid, and from the wash tank the mixed telomer acids are transferred to an acid still where theyare distilled to recover the various products of the process."y From the acid still, telomer diacid and mixed acids are recovered as bottoms fractions, While Vtelomer monoacid product is recovered as an overhead fraction.

The final distillation is performed at a reduced pressure in the range of 1 to 100 mm. Hg absolute.

Referring to the accompanying drawings, in which a diagrammatic illustration `of apparatus in elevation is shown, the reactors 2 and 4 are provided with 'the agitators 6 and 8respectively, which are driven by the motors 10 and 12` The reactors areY also `provided with the` inlet lines 14 and 16 for charging oleum and telomer thereto, and are also provided with `the jackets 18 and 20 for temperature control of the reaction mixture.` Lines 22 and 24 provide means whereby a heat transfer medium may be introduced into the jacketslS and 20 and may be withdrawn through the lines 26 and 2S, respectively. The heat transfer medium may be any of the common materials utilized for this purpose such as Dowtherm for heating and cold water for cooling. Y'

The vapor lines 30 and` 32, respectively, connect the reactors 2 and 4, respectively, with the reilux condensers 34 and 36,`the condensed material from the reflux condensers flowing through the lines 3S and 40, respectively, to the decanters 42 and 44 from which the condensed vapors are returned to the reactors through the lines 46 and 48, except for portions thereof which are withdrawn through the lines 50 and 52 and passed to acid waste or to the drowning tank 54. The uncondensed gases are removed from the condensers 34 and 36 through the lines 56 and 58, respectively, and, as these gases are primarily hydrogen chloride, they are passed to a scrubber, not

' shown, for the recovery thereof.

Y 82, and is washed with water'of dilute hydrochloric acid introduced through the line 84. The product layer from Apol chlgrotruoroethylene laminate, containing 200 m ture, a` separation of: layers; occursA in the'y l0 'fe'fltiins @16v/er." @hier ifprdd Produc tupaersvlfufic acid layer- The upper S111- Temmerex prqduct layer transferred; thereto 76,'v with. any undesiredfporton thereuf Waste, throughihe' line; 18: The eX: acid: leyerfrom they fault "I4: Ypasserl, (i 1hr/.Ouali the. line ,20- A InV the W'ash tankfi, the product;- layer;` isk agitated, by. means of the agitator 80, which is` driven by the motor tihhe'vvash4 tankilspdischarged through the line 86 to the acid storage' 88, any undesired portion thereof being n passed toacd Waste through'the line 90. $215.1 Pcellti g l "'"Erom thefacid storagen88, the mixed acid product is M0 :"T' tllllsfeffed i/hffOUgh th'liitglf 'h'ef abd'Sill l92, in; t

which the mixed acidproductl Vis distilled; withethe telorner 30 Y .0131` 5 Exemple. 15 etramer, having thefrruula *i Cllepcimecli P lyd-,aus; slultl1rzieacid (17431muudsJ 191.1 iiharg'edby Suetiputo 21.25 gallon reactor, regulator. was. adiustedtto, 6 0, p. li` g, and*v waheeted atatemperature ot'220. C. for Y 19 .24.;h9ursf\rith.agitgiou. After coolingrthe flcflfn 'mixture Wastransferred by` pressure through a c zqolevdjranlsfer linetpfa drowningy tank, coated with a .fii The hQt mixture was stirred for `a. period y y ours, to lassist inthe hydrolysis of acid halides andganhydrides, and theY mixture was then allowed to stmldyil-ll 1= 6001. "Ihe lower layer was transferred by means of a pump to a 'holding tank; then the upper aque# ous sulfuric acid. layer, having a concentration of about 40;pe,rcent, `was extactedwith 4, and then 2 gallons of benzene.`, The aqueouseacid wasv discarded after'ianalysis 65 fql gtelorner; acid 3 .3` "mg./l.). The combined product m'ole Monoacrdin the table below:

and diluting the reaction mixture with water to effect the` separation of a product layer and a sulfuric acid layer, separating the products in the product layer, and recovering a telomer acid as a product of the process.

2. A process which comprises hydrolyzing a periiuorochlorinated telomer, having the formula in which n is an integer from 2 to 16, with oleum in a reaction zone at a temperature between about 200 C. and about 225 C. and a pressure between about atmospheric and about 150 pounds per square inch gage cooling the reaction mixture below reaction temperature and diluting the reaction mixture with water to effect the separation of a product layer and a sulfuric acid layer, distilling the product layer, and recovering a compound, having the formula in which n is as given above, as a product of the process.

3. A process which comprises hydrolyzing a perfluorochlorinated telomer, having the formula in which n is an integer from 2 to 16, with oleum in a reaction zone at a temperature between about 200 C. and about 225 C. and a pressure between about atmospheric and about 150 pounds per square inch gage cooling the reaction mixture below reaction temperature and diluting the reaction mixture with water to effect the separation of a product layer and a sulfuric acid layer, distilling the product layer, recovering a compound, having the formula Cl(CF2-CFC1) 1, 1CF ZCO OH in which n is as given above, as one product of the process, and recovering a compound, having the formula in which n is as given above, as a second product of the process.

4. A process which comprises hydrolyzing a perfluorochlorinated telomer with oleum in a reaction zone at an elevated temperature and pressure, to produce a hydrolysis product, said elevated temperature being below the decomposition temperature of said telomer and said hydrolysis product but not substantially below 200 C., transferring the reaction mixture to a dilution zone and adding ice and water thereto to eiiect the separation of a product layer and a sulfuric acid layer, separating the products in the product layer, and recovering a telomer monoacid as a product of the process.

5. A process which comprises hydrolyzing a peruo'rochlorinated telomer with oleum in a reaction zone at an elevated temperature and pressure to produce a hydrolysis product, said elevated temperature being below the decomposition temperature of said telomer and said hydrolysis product but not substantially below 200 C., transferring the reaction mixture to a dilution zone and adding ice and water thereto to eiect the separation of a product layer and a sulfuric acid layer, washing and distilling the product layer, recovering a telomer monoacid as one product of the process, and recovering a telomer diacid as a second product of the process.

6. A process which comprises hydrolyzing a peruorochlorinated telomer with oleum in a reaction zone at an elevated temperature and pressure to produce a hydrolysis product, said elevated temperature being below the decomposition temperature of said telomer and said hydrolysis product but not substantially below 200 C., transferring the reaction mixture to a dilution zone in which it is cooled below reaction temperature and diluted with water to eiect the separation of a product layer and a sulfuric acid layer, washing and distilling the product layer, and recovering a telomer monoacid as one product of the proces-s.

7. A process according to claim l in which the perhalogenated telomer is hydrolyzed in the presence of a telomer acid as an emulsier.

References Cited in the le of this patent UNITED STATES PATENTS 2,398,430 Joyce Apr. 16, 1946 2,440,800 Hanford May 4, 1948 2,559,629 Berry July 10, 1951 2,567,011 Diesslin et al. Sept. 4, 1951 2,695,880 Benning et al. Nov. 30, 1954 2,766,215 Stoops Oct. 9, 1956 

1. A PROCESS WHICH COMPRISES HYDROLYZING A PERFLUOROCHLORINATED TELOMER WITH OLEUM IN A REACTION ZONE AT AN ELEVATED TEMPERATURE AND PRESSURE TO PRODUCE A HYDROLYSIS PRODUCT, SAID ELEVATED TEMPERATURE BEING BELOW THE DECOMPOSITION TEMPERATURE OF SAID TELOMER AND SAID HYDROLYSIS PRODUCT BUT NOT SUBSTANTIALLY BELOW 200*C., COOLING THE REACTION MIXTURE BELOW REACTION TEMPERATURE AND DILUTING THE REACTION MIXTURE WITH WATER TO EFFECT THE SEPARATION OF A PRODUCT LAYER AND A SULFURIC ACID LAYER, SEPARATING THE PRODUCTS IN THE PRODUCT LAYER, AND RECOVERING A TELOMER ACID AS A PRODUCT OF THE PROCESS. 